GCC being built without optimisation

[Michael Hope <michael dot hope at linaro dot org>]

Hi Yann, all.  Someone recently spotted that the crosstool-NG based
Linaro builds took twice as long to compile code than the Ubuntu cross
compiler.  The thread starts here:

 http://lists.linaro.org/pipermail/linaro-toolchain/2012-October/002907.html

and continues at:
 http://lists.linaro.org/pipermail/linaro-toolchain/2012-November/002922.html
 http://lists.linaro.org/pipermail/linaro-toolchain/2012-November/002932.html

It turns out that GCC and the libraries are being built without
optimisation.  scripts/crosstool-NG.sh.in has:

    CT_CFLAGS_FOR_HOST=
    [ "${CT_USE_PIPES}" = "y" ] && CT_CFLAGS_FOR_HOST+=" -pipe"
    CT_CFLAGS_FOR_HOST+=" ${CT_EXTRA_FLAGS_FOR_HOST}"

Setting USE_PIPES or EXTRA_FLAGS turns into passing CFLAGS to
configure turns into overriding the package default of -O2 -g.

This is my hack around:

scripts: set default CFLAGS to optimise.

Our extra CFLAGS override the product defaults, meaning that we build
without optimisation or debug.  Be explicit and add these in.
diff:
=== modified file 'scripts/crosstool-NG.sh.in'
--- scripts/crosstool-NG.sh.in  2012-03-23 05:22:58 +0000
+++ scripts/crosstool-NG.sh.in  2012-11-13 23:50:41 +0000
@@ -488,7 +488,7 @@
     fi

     # Help gcc
-    CT_CFLAGS_FOR_HOST=
+    CT_CFLAGS_FOR_HOST="-O2 -g"
     [ "${CT_USE_PIPES}" = "y" ] && CT_CFLAGS_FOR_HOST+=" -pipe"
     CT_CFLAGS_FOR_HOST+=" ${CT_EXTRA_FLAGS_FOR_HOST}"

-- Michael

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